gistfile1.m

NSURL *url = [NSURL URLWithString:@"http://url/login/"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];

[request setHTTPMethod:@"POST"];
NSMutableString *postData = [[NSMutableString alloc] init];
[postData appendString:@"first_name="];
[postData appendString:[info objectForKey:@"first_name"]];
[postData appendString:@"&last_name="];
[postData appendString:[info objectForKey:@"last_name"]];
[postData appendString:@"&uid="];

[postData appendString:[[info objectForKey:@"uid"] stringValue]];
[postData appendString:@"&gender="];
[postData appendString:[[info objectForKey:@"sex"] stringValue]];
[postData appendString:@"&avatar="];
[postData appendString:[info objectForKey:@"photo_big"]];

NSString *uid = [[info objectForKey:@"uid"] stringValue];
uid = [uid stringByAppendingString:@"CARAMBA"];
NSString *access_token = [uid MD5];

[postData appendString:@"&access_token="];
[postData appendString:access_token];

[request setHTTPBody:[postData dataUsingEncoding:NSUTF8StringEncoding]];